Rachel Reeves is unveiling plans to create “Europe’s Silicon Valley” between Oxford and Cambridge as she stakes the government’s success on kickstarting economic growth and putting more pounds in people’s pockets.The chancellor will announce a blueprint to improve infrastructure across the region that will add up to £78bn to the UK economy within a decade, according to industry experts, and put it at the forefront of science and technological advances.In a major speech to business leaders, she is also expected to confirm plans to expand Heathrow airport, overhaul planning rules and fast-track building projects, but has prompted fears that carbon targets and nature protections are under threat.Reeves has struck a more optimistic tone in recent weeks, after being criticised for undermining confidence following Labour’s election victory last July, by highlighting the Tories’ disastrous economic legacy.Her speech is viewed inside government as an opportunity to pivot away from the economic “doom and gloom” that characterised Labour’s early months and start to focus on delivering real change.However, the latest official data suggests the economy may have flatlined in the second half of 2024, intensifying the pressure on the government to show it can boost growth and improve living standards.Reeves is expected to say the government will go “further and faster” to boost growth, “ending the era of low expectations” and “putting Britain on a different path” with its plans. However, she has spooked some Labour MPs and environmental campaigners with her relentless pursuit of growth.“Britain is a country of huge potential … We are the forefront of some of the most exciting developments in the world like artificial intelligence and life sciences. We have great companies based here delivering jobs and investment in Britain,” she will say.“But for too long, that potential has been held back. For too long, we have accepted low expectations, accepted stagnation and accepted the risk of decline. We can do so much better.“Low growth is not our destiny. But growth will not come without a fight. Without a government that is on the side of working people, willing to take the right decisions now to change our country’s course for the better.”Economists have suggested that two of the most immediate ways to boost growth would be higher migration and a better trading relationship with the European Union, neither of which Reeves is expected to address in her speech.Reeves’ decision to revive the Oxford-Cambridge corridor marks a return to political favour for a scheme shelved three years ago by Boris Johnson in order to prioritise levelling up spending in the north of England.Sir Patrick Vallance, the science minister, will oversee the plan. He said: “The UK has all the ingredients to replicate the success of Silicon Valley or the Boston Cluster but for too long has been constrained by short-termism and a lack of direction